Democratic Sen. Dianne Feinstein of California joined an exclusive club including Hillary Clinton and Democratic Sen. Elizabeth Warren of Massachusetts on Wednesday when President Donald Trump christened her with a nickname on his Twitter account.

“Crooked Hillary” and “Pocahontas” are now joined by “Sneaky Dianne Feinstein,” who Trump described as “underhanded” for disclosing details behind a controversial dossier allegedly tying the president to Russia during his campaign.

The tweet came one day after the longtime California senator — whose suggestion last summer that Trump could be a “good president” if he changed his ways was a source of outrage for many — released the transcript of a closed-door Senate committee interview about the dossier on Tuesday.

There’s much to unpack from the events that led up to the tweet and her new nickname, so let’s get to it.

What did Feinstein do?

Feinstein is the ranking Democrat on the Senate Judiciary Committee, which interviewed the head of a research firm called Fusion GPS in August. Fusion GPS, which has worked with both Democrats and Republicans, was hired during the 2016 election by a lawyer for Hillary Clinton’s presidential campaign to do opposition research on Trump, which resulted in a dossier filled with allegations against him.

You might remember that the dossier — which alleges Russia and Trump colluded during the election — was a huge deal during the election, especially because Buzzfeed published the unsubstantiated claims. (We should add here that a Trump lawyer sued Buzzfeed on Tuesday for defamation for publishing the dossier.)

Reporters, analysts and others have long held interest in, debated and questioned the dossier, which is why Feinstein decided to release the transcript from the judiciary committee’s interview with Fusion GBS founder Glenn Simpson.

“After speaking with majority and minority committee staff for 10 hours, Glenn Simpson requested the transcript of his interview be released publicly. The American people deserve the opportunity to see what he said and judge for themselves,” said Feinstein. “The innuendo and misinformation circulating about the transcript are part of a deeply troubling effort to undermine the investigation into potential collusion and obstruction of justice. The only way to set the record straight is to make the transcript public.”

What did the transcript say?

One of the key findings is that the dossier was handed over to the FBI in 2016 by Christopher Steele, the former British spy who created it, because he was worried about “whether a political candidate was being blackmailed,” according to the newly released transcript.

What has been the reaction to Feinstein’s move?

“Her action undermines the integrity of the committee’s oversight work and jeopardizes its ability to secure candid voluntary testimony relating to the independent recollections of future witnesses," a spokesperson for Grassley said.

He and Sen. Lindsey Graham, R-South Carolina, asked the Justice Department last week to investigate Steele for allegedly making false statements to the government.

Trump has denied everything from the dossier, calling it a “pile of garbage” and tweeting on Wednesday that Feinstein’s move is just another chapter in the “single greatest witch hunt in American history.”

Why does any of this matter?

Trump and others believe the controversial dossier triggered the FBI’s investigation into Russia’s meddling in the 2016 election.

Fusion GPS officials say they were told the dossier was taken seriously because the FBI had allegedly already heard similar reports to the ones made by Steele. The Fusion GPS official interviewed by Congress said so in the transcript released by Feinstein.

“My understanding was that they believed Chris (Steele) at this point — that they believed Chris might be credible because they had other intelligence that indicated the same thing and one of those pieces of intelligence was a human source from inside the Trump organization,” he said, according to the transcript.

Steele also contacted reporters about his findings, which is another source of controversy in Washington, and one of the reasons Grassley and Graham want him investigated.

“After reviewing how Mr. Steele conducted himself in distributing information contained in the dossier and how many stop signs the Department of Justice ignored in its use of the dossier, I believe that a special counsel needs to review this matter” Grassley said.

Did you follow all of that? There’s a lot to consider, but one thing that’s clear is that Trump isn’t happy the transcript of the interview Fusion GPS got out.

On the other hand, many were rooting Feinstein on or pointing out how her new nickname might benefit her 2018 campaign, in which she faces a primary challenge from a fellow Democrat, California Senate President Kevin deLeón. Others joked around about it.